Heat sealing machine



July 5, 1955 R. E. STANTON 2,712,343

HEAT SEALING MACHINE Filed July 14, 1953 INVENTOR. Robert E. Szanfon ATTORNEYS.

United States Patent 2,712,343 HEAT SEALING MACHINE Robert E. Stanton, Bloomfield, N. J., assignor to Celanese Corporation of America, New York, N. Y., a corporation of Delaware Application July 14, 1953, Serial No, 367,908 1 Claim, (Cl, 154-42 This invention relates to heat sealing and relates more particularly to an improved apparatus for tem of rolls, and formed into a sleeve, having overlapping edges, on of the sleeve is then stopped, the leading end of the sleeve each other. the film for a very short time, and it is dilficult to obtain a seal.

It is an object of this invention for the heat sealing of relatively which will be advantages.

A further object of this invention is the provision of a novel apparatus for the heat sealing of relatively thin films to one another which is eflicient in operation and relatively simple in construction.

Other objects of this invention will be apparent from the following detailed description and claims.

A preferred form of this invention is illustrated in the accompanying drawing which shows an elevational view of the heat sealing apparatus in cross-section.

Referring now to the drawing, reference numerals 11 and 12 designate the overlapping edges of a film 13 made of a thermoplastic material such as cellulose acetate. This film is supported on a plate 14 having a covering of sheet of which is a layer of glass cloth 17 e. g. about A second, consistently strong flat to provide an apparatus thin films to one another free from the foregoing and other disthe heat to an elongated sealing iron 21 supported by said block. The upper portion of the sealing iron 21 is relatively wide and is in close contact with the block 19 so that there is good heat transfer between said block and said upper portion. Desirably, there is a suitable thermostat (not shown), at or near the interface of the block 19 and the sealing iron 21, for controlling the heat output of the core heater 18. The intermediate portion of the sealing iron 21 is tapered to a relatively narrow waist 22, while the bottom portion of the sealing iron is broad in crosssection,

plate 23 having a convex lower sealing face 24. The sealing iron of this invention may be of any desired size. In one form of said /2 inch or 1 inch; at its center, is equal to about A; of said width; and the width of the Waist 22 is also about equal to about /8 of the width of said sole plate. The waist 22 and sole plate 23, as well as the core heater 18, the block 19 and the upper portion of the sealing iron 21, extend the entire length of the desired seal, e. g. about 6 to 15 inches.

It will be readily seen that the block 19 passes the sole plate 23 of said sole plate.

heat flowing from the through the waist 22 to the center of and then to the tapered side portions Accordingly, the center of the sealing face 24 will be at a higher temperature than the edges of said face. Desirably, the sealing face is coated with polytetrafluoroethylene or other similar material which does not adhere to heated cellulose acetate.

in operation, the block 19 is moved downward to press the heated sealing face 24 against the upper surface of the film 13. This pressure causes the rubber layer 16 to yield sufiiciently so that substantially the entire sealing face 24 is in contact with the film 13.

the temperature of said edges is reduced below the sealing temperature, as desired. Thereafter, the apparatus oprates to produce a consistently strong fiat seal.

It is to be understood that the foregoing detailed description is given merely by way of illustration and parting from the spirit of my invention.

Having described my invention, what I desire to secure by Letters Patent is:

In an apparatus for the heat-sealing of thermoplastic sole plate. 

